Kids do ask some amazing questions. I am no expert on child psychology. I am just a philosopher who is also a parent. So please do not take what I will say the wrong way. I do not really mean to be giving parenting advice here. To some extent, what you should tell your son depends upon your religious beliefs. Some traditions would hold that your son was with God, waiting to be embodied. Some would hold that your son may have had a prior life, about which you would not know very much. But I am guessing that none of these traditions is yours, since otherwise the answer to the question would be clear enough. So I will answer assuming that you believe that, prior to your son's birth, he did not exist. (Note that many religious traditions would hold this view. So this is not a religious vs non-religious issue.) So, telling your son the truth would mean saying something like this: We can make cookies, but before we make the cookies, there aren't any cookies. There is flour and butter and...

And one might add that the cells themselves are hardly immune from "renewal" at the molecular level. So the short version is: If identity requires complete coincidence of matter, then essentially nothing but sub-atomic particles survive over any reasonable stretch of time. That does rather suggest, though the contrary view is certainly held, that identity over time simply does not require complete coincidence of matter. What it does require is not very clear, but that is no reason to despair. Of course, the question didn't ask about complete coincidence of matter. But it's unclear why anything less might suffice. And, if it does, then you run into issues about transitivity: A might share much of its matter with B, which shares much of its matter with C; but A and C do not share much of their matter.

I'd suggest that this puzzle is largely a linguistic one. Consider the relation being larger than . Can one perceive that relation? There's a temptation to say that one cannot perceive the relation itself , because the relation itself "has no color or visual size or shape", and so on and so forth. And maybe that's so. Ask a metaphysician. (Of course, what answer you get will depend upon which metaphysician you ask!) But the examples with which you began suggest a different question. Can one perceive that one thing is larger than another? Here, it seems to me, the answer is clearly that one can. We perceive that kind of thing all the time. But how can we perceive the relation if we can't perceive the relation itself? The answer, I think, is that this question is just confused. What we perceive is that the objects are so related . Perception, as people sometimes put it, has propositional content, and relations figure in these contents. One might yet wonder how it is that we manage to...

Teams, surely, cannot exist without individuals to play on them, but it isn't obvious to me, anyway, that teams don't "really" exist. It was the same team that won the World Series in 2004 as had last wonit in 1918, so there has to be something more to a team than just acollection of players. Teams can gain and lose players, change locations and ownership, even change names, and yet it can be the same team. The question you are asking can perhaps be clarified if we introduce the idea of a fusion , which is a notion from merology, the logic of parts and wholes. Suppose we have a bunch of objects, say, a shoe, a tennis ball, and a neutron star. The fusion of these objects is, by definition, simply the "sum" of these three objects. It's tempting to say that it is the object whose only parts are the shoe, the ball, and the star, but that's not quite right, because the parts of the shoe are also parts of the fusion. Moreover, the scattered thing consisting of half the tennis ball and the sole of...

There's another distinction that needs to be made here and that is relevant to the objection to explanation (1): We need to distinguishdifferent sorts of necessity. Nowadays, most philosophers and logicianswould agree that there is nothing whose existence is logically necessary, even the objects of mathematics, although their existence is mathematically and even metaphysically necessary. Even God's existence would not be regarded as logically necessary, even by philosophers who accept God's existence. Perhaps we should regard it as agreed, then, that, if God exists, God exists by metaphysical necessity. If so, then there is no contradiction in holding that it is logically possible that God should have existed. Whether it is consistent to hold that it is metaphysically possible that God should have existed depends upon whether one thinks the so-called Brouweresche axiom of modal logic holds for metaphysical necessity. (Axiom B says that, if it is possible that it is necessary that A,...

This is a version of an old problem, one discussed endlessly by theologians. In its simplest form, it goes like this: Can God make a rock both big and small? Obviously not. So God isn't omnipotent. If you think that's a cheat, I'm with you. It's not possible for there to be a rock that is both big and small, so it's not limit on God's power that God can't make a rock like that. We have to be more careful in how we understand omnipotence. It's a delicate question how we should understand it, but a first stab might be: A being is omnipotent if, whenever it is possible that p, that being can bring about that p. The puzzle your roommate presents you is of this same form. If Fred is omnipotent, then it simply isn't possible for a rock to be so big that Fred can't lift it. So it's no limit on Fred's power that he can't create a rock that big. Of course, maybe Fred isn't omnipotent, and maybe it's not even possible for there to be a being that is omnipotent. But the argument your roommate offered does...

There are many different conceptions of "opposite" at work in your question. One, with which your son seems to have been operating, is similar to what Aristotle would have called "contrary". Two properties are contraries if it is impossible for them to be present in the same object at the same time, and at least one of them must be present. A weaker conception would be that of a "contradictory", for which only the first clause applies: They can't both be present. The conception of a contrary that your example of the vase employs, however, is spatial or perhaps (to use a technical terms) "merological", that is, defined in terms of parts and wholes. So let us ask: What is the opposite of you?Non-you? And what is non-you? The sum total of everything that is notpart of you? If that's counts as your "opposite", then, yes, everythinghas an opposite, but note that we are operating with the spatial or mereological sense of opposite, not the Aristotelian sense. It's not very interesting that...

I wish I had something helpful to say about this, but I don't know if I do. We should, however, try to get a little clearer on what is at issue. Let's consider something a little simpler, like plays. I think A Comedy of Errors exists. That is, I think there is such a thing as A Comedy of Errors . But that play isn't a physical thing. You can't tear it up, burn it, or spill your coffee on it, though you can tear up, burn, and soak printings of it. If one wants to say that A Comedy of Errors therefore doesn't exist in the same way that its printings do, I suppose that's all right. But that's not because there is some special sense of "exists" at work here. It's because a play is a very different sort of thing from a printing of one. I take it that the same is true of God. God (if God exists) isn't a physical object, so one wouldn't expect God to be made of atoms. What is it that even atheists will concede about God? Let's look at what you say about France. If you are thinking of France as...